Hesam Najibi - Academia.edu (original) (raw)

Papers by Hesam Najibi

Research paper thumbnail of Correlation and Prediction of Solubility of CO2 in Amine Aqueous Solutions

Iranian Journal of Chemistry & Chemical Engineering-international English Edition, Mar 1, 2010

The solubility of CO 2 in the primary, secondary, tertiary and sterically hindered amine aqueous ... more The solubility of CO 2 in the primary, secondary, tertiary and sterically hindered amine aqueous solutions at various conditions was studied. In the present work, the Modified Kent-Eisenberg (M-KE), the Extended Debye-Hückel (E-DH) and the Pitzer models were employed to study the solubility of CO 2 in amine aqueous solutions. Two explicit equations are presented to evaluate the concentration of H + as well as the equilibrium constants of protonation reactions for the tertiary and sterically hindered amine aqueous solutions. Using the M-KE model, the equilibrium constants of protonation reactions of amines were correlated in terms of temperature, CO 2 partial pressure and amine concentration. Also the E-DH and Pitzer models were used to correlate the solubility of CO 2 in MDEA aqueous solution. The binary interaction parameters for the models studied in this work as well as the parameters for the equilibrium constants of protonation reactions were obtained using the Davidon-Fletcher-Powell (DFP) minimization method. The results show that the M-KE, E-DH and the Pitzer models can accurately predict the corresponding experimental data. Although the solubility data for CO 2 in amine aqueous solutions have been reported in the literature to a large extent, accurate data are required to model the CO 2 absorption process. Therefore, two criteria for the tertiary and sterically hindered amines were presented using the M-KE model to screen the experimental data.

Research paper thumbnail of Experimental investigation of methane hydrate formation in the presence of copper oxide nanoparticles and SDS

Journal of Natural Gas Science and Engineering, Mar 1, 2015

Worldwide demand for natural gas (mainly composed of methane) is ever increasing, therefore; prod... more Worldwide demand for natural gas (mainly composed of methane) is ever increasing, therefore; production and transmission of natural gas from stranded reservoirs becomes increasingly attractive. However, one of the challenges facing the development of these reservoirs is transportation of the produced gas to the market in a safe, efficient and cost-effective manner. Gas hydrates have been considered as a good alternative for storage and transportation media of natural gas produced from the stranded reservoirs, but the most disadvantage of this method is the slow rate of hydrate formation although addition of surfactants and nanoparticles will promote this formation process. In this work, the effects of sodium dodecyl sulfate (SDS) and CuO nanoparticles on the hydrate behavior of methane at 274.65 and 276.65 K temperatures; 5 and 6 MPa initial pressures and in a wide range of concentrations of nanoparticle in aqueous solution have been studied. The results show that by adding these materials, the amounts of gas consumption, the rate of gas consumption and the mole percent of water to hydrate conversion have increased, where this increase is proportional to the nanoparticle concentration used. The results also demonstrate that adding these materials have decreased the induction times, however, have no appreciable effect on the final gas-storage capacity.

Research paper thumbnail of Experimental measurement and thermodynamic modelling of phase equilibria of semi-clathrate hydrates of (CO2+tetra-n-butyl-ammonium bromide) aqueous solution

The Journal of Chemical Thermodynamics, Aug 1, 2015

ABSTRACT Comprehensive studies on semi-clathrate hydrates phase equilibria are still required to ... more ABSTRACT Comprehensive studies on semi-clathrate hydrates phase equilibria are still required to better understand characteristics of this type of clathrates. In this communication, new experimental data on the dissociation conditions of semi-clathrate hydrates of {carbon dioxide + tetra-n-butyl-ammonium bromide (TBAB)} aqueous solution are first reported in a wide range of TBAB concentrations and at different pressures and temperatures. A thermodynamic model is then proposed to predict the dissociation conditions of the semi-clathrate hydrates for the latter system. The hydrate – TBAB aqueous solution (H-Lw) phase equilibrium prediction is considered based on Gibbs energy minimization approach. A modified van der Waals–Platteeuw solid solution theory developed based on the H-Lw equilibrium information is employed to predict the dissociation conditions of semi-clathrate hydrates of carbon dioxide + TBAB. The properties of the aqueous solution are estimated using the AMSA-NRTL electrolyte model (Considering the association and hydration of ions). The Peng–Robinson equation of state is used for estimating the gas/vapour phase properties. Results show that the proposed model satisfactorily predicts the experimental values with an average absolute relative deviation of approximately 13%.

Research paper thumbnail of Application of artificial neural networks for estimation of solubility of acid gases (H2S and CO2) in 32 commonly ionic liquid and amine solutions

Journal of Natural Gas Science and Engineering, May 1, 2015

Abstract In the present study, the potential use of a model based on an artificial neural network... more Abstract In the present study, the potential use of a model based on an artificial neural network (ANN) was investigated to predict the solubility of acid gases (H2S and CO2) in 32 commonly single and mixed amine and ionic liquid (IL) solutions over wide ranges of operating conditions. Temperature, partial pressure of acid gas (H2S or CO2), overall mass concentration, apparent molecular weight, critical temperature and critical pressure of solution were chosen as input variables of the proposed network. A collection of 733 experimental data points for H2S solubility (including train, test and validation data points) have been gathered from the literature to develop the network. The best parameters of the developed ANN containing the number of neurons, numbers of hidden layer and transfer function were acquired by using these data points. To evaluate the network accuracy, regression analysis with a data set including 169 data points for H2S solubility which were not considered in the training, testing and validation stages was applied. Furthermore, the extrapolation capability of the network was investigated by an extra data set (114 data points for CO2 solubility). The optimized network was trained by the Levenberg–Marquardt back-propagation algorithm with two hidden layers including 8 and 4 neurons and Tan-sigmoid transfer function for the hidden and output layers. The model results show that developed ANN model has ability to estimate accurately the solubility of acid gases in different solutions with Mean Relative Error (MRE) value of 3.104 and correlation coefficient (R2) of 0.997.

Research paper thumbnail of Correlation and Prediction of the Solubility of CO2 and H2S in an Aqueous Solution of 2-Piperidineethanol and Sulfolane

Industrial & Engineering Chemistry Research, 1998

The simplified Clegg-Pitzer equations are used to correlate the solubility data of COâ in the 2-P... more The simplified Clegg-Pitzer equations are used to correlate the solubility data of COâ in the 2-PE (2-piperidineethanol) (45 wt %)-TMS (sulfolane) (40 wt %)-HâO (15 wt %) system at 25, 40, 70, 100, and 130 C and the solubility data of HâS in the 2-PE (45 and 55 wt %)-TMS (40 and 10 wt %)-HâO (15 and 35 wt %) systems at 40 and 100 C. The interaction parameters thus determined can be used to predict the solubility data for the COâ-2-PE (55 wt %)-TMS (10 wt %)-HâO (35 wt %) system at 40 and 100 C and also for the quinary COâ-HâS-2-PE-TMS-HâO system without any additional adjustable parameters. The equations have been proven again to be of use for aqueous solutions containing mixed physical and chemical solvents and ionic species with chemical equilibria.

Research paper thumbnail of Experimental Investigation of Methane Hydrates Equilibrium Condition in the Presence of KNO3, MgSO4, and CuSO4

Journal of Chemical & Engineering Data, 2010

Worldwide demand for natural gas (mainly composed of methane) is ever increasing, therefore; prod... more Worldwide demand for natural gas (mainly composed of methane) is ever increasing, therefore; production and transmission of natural gas from stranded reservoirs becomes increasingly attractive. However, one of the challenges facing the development of these reservoirs is transportation of the produced gas to the market in a safe, efficient and cost-effective manner. Gas hydrates have been considered as a good alternative for storage and transportation media of natural gas produced from the stranded reservoirs, but the most disadvantage of this method is the slow rate of hydrate formation although addition of surfactants and nanoparticles will promote this formation process. In this work, the effects of sodium dodecyl sulfate (SDS) and CuO nanoparticles on the hydrate behavior of methane at 274.65 and 276.65 K temperatures; 5 and 6 MPa initial pressures and in a wide range of concentrations of nanoparticle in aqueous solution have been studied. The results show that by adding these materials, the amounts of gas consumption, the rate of gas consumption and the mole percent of water to hydrate conversion have increased, where this increase is proportional to the nanoparticle concentration used. The results also demonstrate that adding these materials have decreased the induction times, however, have no appreciable effect on the final gas-storage capacity.

Research paper thumbnail of Experimental determination and prediction of methane hydrate stability in alcohols and electrolyte solutions

Fluid Phase Equilibria, 2009

Research paper thumbnail of An Evaluation of Four Electrolyte Models for the Prediction of Thermodynamic Properties of Aqueous Electrolyte Solutions

DOAJ (DOAJ: Directory of Open Access Journals), Apr 1, 2017

In this work, the performance of four electrolyte models for the prediction of the osmotic and ac... more In this work, the performance of four electrolyte models for the prediction of the osmotic and activity coefficients of different aqueous salt solutions at a temperature of 298 K, at atmospheric pressure, and in a wide range of concentrations is evaluated. In two of these models, namely electrolyte non-random two-liquid (e-NRTL) and mean spherical approximation non-random two-liquid (MSA-NRTL), the association between ions of the opposite charges for simplification purposes is ignored, but in the other two ones, namely associative mean spherical approximation non-random two-liquid (AMSA-NRTL) and binding mean spherical approximation (BiMSA), association and solvation effects are considered. The predictions of these four models for the osmotic and activity coefficients of electrolyte solutions at a temperature of 298 K and at atmospheric pressure are compared with the experimental data reported in the literature. This comparison is performed for 28 different aqueous salt solutions, including thio-cyanates, perchlorates, nitrates, hydroxides, quaternary ammonium salts, and others. The results show that the performance of the models which consider association effects is better than the others, especially for higher salt concentrations. However, the best performance belongs to the BiMSA model, which has some parameters with physical meaning.

Research paper thumbnail of Investigating the kinetics of CO2 absorption in aqueous sodium serinate/piperazine solutions: An experimental and mathematical modeling

Journal of environmental chemical engineering, Dec 1, 2022

Research paper thumbnail of Investigating the kinetics of CO2 absorption in aqueous sodium serinate/piperazine solutions: An experimental and mathematical modeling

Journal of Environmental Chemical Engineering

Research paper thumbnail of An Evaluation of Four Electrolyte Models for the Prediction of Thermodynamic Properties of Aqueous Electrolyte Solutions

Iranian Journal of Oil and Gas Science and Technology, 2017

In this work, the performance of four electrolyte models for prediction the osmotic and activity ... more In this work, the performance of four electrolyte models for prediction the osmotic and activity coefficients of different aqueous salt solutions at 298 K, atmospheric pressure and in a wide range of concentrations are evaluated. In two of these models, (electrolyte Non-Random Two-Liquid e-NRTL and Mean Spherical Approximation-Non-Random Two-Liquid MSA-NRTL), association between ions of opposite charges for simplification purposes is ignored and in the other two ones, (Associative Mean Spherical Approximation-Non-Random Two-Liquid AMSA-NRTL and Binding Mean Spherical Approximation BiMSA) association and solvation effects are considered. The predictions of these four models for the osmotic and activity coefficients of electrolyte solutions at 298 K and atmospheric pressure are compared with the experimental data reported in the literature. This comparison includes, 28 different aqueous salt solutions including thio-cyanates, perchlorates, nitrates, hydroxides, quaternary ammonium sal...

Research paper thumbnail of Natural gas hydrate stability conditions and water activity in aqueous solutions containing mono ethylene glycol (MEG) and salt: Experimental measurements and thermodynamic modeling

Fluid Phase Equilibria, 2021

Research paper thumbnail of Decrease in evaporative loss of volatile fuels using new mixture of surfactants

Petroleum Science and Technology, 2021

Abstract Despite the economic aspects of evaporative losses of volatile hydrocarbons such as gaso... more Abstract Despite the economic aspects of evaporative losses of volatile hydrocarbons such as gasoline, problems in the form of fire hazards and environmental pollutions are also concerned. Today many options to reduce the evaporation of hydrocarbon liquids are offered and used worldwide but none of them can impressively prevent the process. In this work, the potential use of mixture of surfactants as liquid film coating layer on free surface of volatile fuels was investigated to decrease the evaporative loss of gasoline and oil in fuel tanks. A combination of surfactants and polyethylene glycol were considered as liquid film that can be applied to spread on the surface of gasoline and oil. The prepared liquid film can remain on the surface of gasoline for about 5 hr and on the surface of oil for more than 55 hr. Obtained results indicate that by using the covering film, the evaporation losses of gasoline and oil at 25° C and atmospheric pressure in a time interval of 200 min are reduced by 20.92 and 70.83%, respectively. So, using a mixture of surfactant and polymer (as a covering film) can reduce the evaporation loss of hydrocarbons appreciably. The use of non-carcinogenic surfactants, increasing the durability of the coating layer on the gasoline surface and significantly reducing the evaporative loss of gasoline are some of the innovations of this research.

Research paper thumbnail of Experimental measurement and prediction of carbon dioxide clathrate hydrate phase boundary in presence of ethanol + sodium chloride, potassium chloride, magnesium chloride and calcium chloride aqueous solution

Petroleum Science and Technology, 2019

The dissociation condition of clathrate hydrate of carbon dioxide in aqueous solutions of ethanol... more The dissociation condition of clathrate hydrate of carbon dioxide in aqueous solutions of ethanol þ NaCl, KCl, MgCl 2 and CaCl 2 are measured in the temperature range of (259.4-274.7) K and pressures up to 3.7 MPa. Isochoric pressure-search method is used for all measurements. In addition for the first time in open literature a machine learning algorithm model based on artificial neural network is developed to predict equilibrium temperatures. Absolute relative deviation (ARD) and correlation coefficient (R 2) for trained neural network are 0.0305 and 0.9994, respectively.

Research paper thumbnail of Prediction of acid gas solubility in amine, ionic liquid and amino acid salt solutions using artificial neural network and evaluating with new experimental measurements

Journal of Natural Gas Science and Engineering, 2016

Abstract In this work presented here attempt is prediction of acid gases (carbon dioxide and hydr... more Abstract In this work presented here attempt is prediction of acid gases (carbon dioxide and hydrogen sulfide) loading capacities by employing artificial neural network (ANN) model in 51 single and blended alkanolamine, ionic liquid and amino acid salt solutions as commonly and new industrial absorbents in large domain of operational conditions. Also for evaluating extrapolation capability of ANN, new experimental data on CO2 solubility in aqueous solutions of Potassium Glycinate blended with Piperazine (PZ) and 2-amino-2-methyl-1-propanol (AMP) at different temperatures and pressures are measured. It should be mention that CO2 solubility data for these two solutions are not available in literature. For developing ANN, solution pH, total mass concentration, partial pressure of CO2 and H2S, apparent molecular weight, critical temperature, critical pressure and temperature are assumed as inputs. A band of 2982 experimental data points for CO2 and H2S loading capacities have been collected from literature to create the suggested ANN. The best structure of the suggested network is achieved by employing these literature data points. The network is trained by algorithm of Levenberg–Marquardt back-propagation, consists of 9 and 6 neurons in first and second hidden layers, respectively. For the hidden and output layers, Tan-sigmoid transfer function is utilized. The output results of developed network show that suggested network that is created with solubility data of single and blended alkanolamine, ionic liquid and amino acid salt solutions has capability to predict accurately CO2 and H2S loading capacities in dissimilar commonly and new industrial solutions with Average Relative Deviation (ARD %) equal to 2.7992, Mean Square Error (MSE) value of 3.7468 × 10−5 and correlation coefficient (R2) equal to 0.9984.

Research paper thumbnail of CO 2 solubility in aqueous solutions of potassium prolinate and (potassium prolinate + 2-amino-2-methyl-1-propanol) as new absorbents

Journal of Natural Gas Science and Engineering, 2016

Please cite this article as: Hamzehie, M.E., Najibi, H., CO 2 solubility in aqueous solutions of ... more Please cite this article as: Hamzehie, M.E., Najibi, H., CO 2 solubility in aqueous solutions of potassium prolinate and (potassium prolinate + 2-amino-2-methyl-1-propanol) as new absorbents,

Research paper thumbnail of Prediction of carbon dioxide loading capacity in amino acid salt solutions as new absorbents using artificial neural network and Deshmukh–Mather models

Journal of Natural Gas Science and Engineering, 2015

The aim of this work issolubility prediction of carbon dioxide (CO 2) in amino acid salt solution... more The aim of this work issolubility prediction of carbon dioxide (CO 2) in amino acid salt solutions as new absorbents over wide ranges of operating conditions, utilizing Artificial Neural Network (ANN) and Deshmukh-Mather models. pH of solutions, overall molar concentration, partial pressure of CO 2 , apparent molecular weight and temperature was picked as input variables of the proposed ANN. A group of 1364 literature experimental data points for CO 2 solubility have been congregated from the literature to build the network. The best architecture of the developed ANN including the numbers of hidden layer, transfer function and number of neurons were attained by utilizing these literature data points. Also CO 2 solubility in amino acid salt solution was modeled using Deshmukh-Mather model. Results show that proposed ANN has better performance compared to Deshmukh-Mather model.The ANN was trained by the Levenberg-Marquardt backpropagation algorithm including two hidden layers with 8 and 7 neurons and Tan-sigmoid transfer function for the hidden and output layers. The model results show that proposed ANN that developed with amino acid salt solutions data points has ability to predict accurately the

Research paper thumbnail of Experimental and theoretical study of carbon dioxide solubility in aqueous solution of potassium glycinate blended with piperazine as new absorbents

Journal of CO2 Utilization, 2016

Abstract In this work aqueous solution of potassium glycinate, piperazine and potassium glycinate... more Abstract In this work aqueous solution of potassium glycinate, piperazine and potassium glycinate blended with piperazine have been utilized through CO 2 solubility measurements in order to investigate the possible use of these salts of amino acid blended with alkanolamine for CO 2 absorption. The equilibrium solubility of CO 2 for aqueous solutions of potassium glycinate, piperazine and potassium glycinate blended with piperazine at 1.0, 4.0 and 10.0 wt.% overall mass concentration are experimentally measured with an equilibrium cell at CO 2 partial pressure ranging from 5.1 to 2508.7 kPa and temperatures between 293.15 and 323.15 K. Obtained data show that loading capacity decreases with increase in temperature and concentration of potassium glycinate and potassium glycinate blended with piperazine. Obtained CO 2 loadings are very high at low concentration of potassium glycinate. In order to predict CO 2 solubility in aqueous solutions potassium glycinate, piperazine and potassium glycinate blended with piperazine, Deshmkh-Mather model is extended. The values of MSE, ARD and R 2 for the extended Deshmukh-Mather model are 0.0741, 8.9582 and 0.9826, respectively. In addition, an artificial neural network (ANN) is developed to predict CO 2 solubility in aqueous solutions of piperazine, potassium glycinate and potassium glycinate blended with piperazine. The values of MSE, ARD and R 2 for the optimal trained ANN are 0.0179, 4.1528 and 0.9962, respectively.

Research paper thumbnail of Theoretical and experimental study of phase equilibrium of semi-clathrate hydrates of methane + tetra-n-butyl-ammonium bromide aqueous solution

Journal of Natural Gas Science and Engineering, 2015

Abstract In this study, the phase stability conditions of semi-clathrate hydrate of methane + tet... more Abstract In this study, the phase stability conditions of semi-clathrate hydrate of methane + tetra-n-butyl-ammonium bromide (TBAB) + water system is investigated. New experimental data on the hydrate–liquid–vapor equilibrium conditions of this system is measured. The measured data is for the pressure range of 2.88–14.1 MPa, temperature range of 285.6–295.9 K and TBAB mass fractions of 0.05, 0.15 and 0.3. A thermodynamic model is also developed to predict the phase stability conditions of hydrate for this system. In the developed model, the phase equilibrium of the hydrate of pure TBAB in water is predicted based on the Gibbs free energy minimization technique. This model is then combined with the statistical thermodynamic model of van der Waals–Platteeuw (vdW–P) to predict the phase stability conditions of semi-clathrate hydrate of methane with TBAB in aqueous solution. Binding mean spherical approximation (BiMSA) electrolyte model is used for aqueous phase properties prediction and modified Peng–Robinson equation of state (PR-EoS) is used for calculation of the gaseous phase properties. The results show that the developed model satisfactorily predicts the experimental data with Average Absolute Relative Deviation (AARD) of 12%. Moreover, the model is able to predict the different types of pure TBAB semi-clathrate hydrates and also the inhibition and promotion effects of this salt. The results also show that considering the association effect in the electrolyte model, can improve the predictions of the developed thermodynamic model for hydrate phase equilibrium of methane in the presence of TBAB aqueous solution.

Research paper thumbnail of Carbon dioxide loading capacity in aqueous solution of Potassium salt of Proline blended with Piperazine as new absorbents

Thermochimica Acta, 2016

Research Highlights  CO2 solubility in solutions of potassium prolinate + piperazine is measured... more Research Highlights  CO2 solubility in solutions of potassium prolinate + piperazine is measured.  Solution of potassium prolinate + piperazine has very high loading capacity.

Research paper thumbnail of Correlation and Prediction of Solubility of CO2 in Amine Aqueous Solutions

Iranian Journal of Chemistry & Chemical Engineering-international English Edition, Mar 1, 2010

The solubility of CO 2 in the primary, secondary, tertiary and sterically hindered amine aqueous ... more The solubility of CO 2 in the primary, secondary, tertiary and sterically hindered amine aqueous solutions at various conditions was studied. In the present work, the Modified Kent-Eisenberg (M-KE), the Extended Debye-Hückel (E-DH) and the Pitzer models were employed to study the solubility of CO 2 in amine aqueous solutions. Two explicit equations are presented to evaluate the concentration of H + as well as the equilibrium constants of protonation reactions for the tertiary and sterically hindered amine aqueous solutions. Using the M-KE model, the equilibrium constants of protonation reactions of amines were correlated in terms of temperature, CO 2 partial pressure and amine concentration. Also the E-DH and Pitzer models were used to correlate the solubility of CO 2 in MDEA aqueous solution. The binary interaction parameters for the models studied in this work as well as the parameters for the equilibrium constants of protonation reactions were obtained using the Davidon-Fletcher-Powell (DFP) minimization method. The results show that the M-KE, E-DH and the Pitzer models can accurately predict the corresponding experimental data. Although the solubility data for CO 2 in amine aqueous solutions have been reported in the literature to a large extent, accurate data are required to model the CO 2 absorption process. Therefore, two criteria for the tertiary and sterically hindered amines were presented using the M-KE model to screen the experimental data.

Research paper thumbnail of Experimental investigation of methane hydrate formation in the presence of copper oxide nanoparticles and SDS

Journal of Natural Gas Science and Engineering, Mar 1, 2015

Worldwide demand for natural gas (mainly composed of methane) is ever increasing, therefore; prod... more Worldwide demand for natural gas (mainly composed of methane) is ever increasing, therefore; production and transmission of natural gas from stranded reservoirs becomes increasingly attractive. However, one of the challenges facing the development of these reservoirs is transportation of the produced gas to the market in a safe, efficient and cost-effective manner. Gas hydrates have been considered as a good alternative for storage and transportation media of natural gas produced from the stranded reservoirs, but the most disadvantage of this method is the slow rate of hydrate formation although addition of surfactants and nanoparticles will promote this formation process. In this work, the effects of sodium dodecyl sulfate (SDS) and CuO nanoparticles on the hydrate behavior of methane at 274.65 and 276.65 K temperatures; 5 and 6 MPa initial pressures and in a wide range of concentrations of nanoparticle in aqueous solution have been studied. The results show that by adding these materials, the amounts of gas consumption, the rate of gas consumption and the mole percent of water to hydrate conversion have increased, where this increase is proportional to the nanoparticle concentration used. The results also demonstrate that adding these materials have decreased the induction times, however, have no appreciable effect on the final gas-storage capacity.

Research paper thumbnail of Experimental measurement and thermodynamic modelling of phase equilibria of semi-clathrate hydrates of (CO2+tetra-n-butyl-ammonium bromide) aqueous solution

The Journal of Chemical Thermodynamics, Aug 1, 2015

ABSTRACT Comprehensive studies on semi-clathrate hydrates phase equilibria are still required to ... more ABSTRACT Comprehensive studies on semi-clathrate hydrates phase equilibria are still required to better understand characteristics of this type of clathrates. In this communication, new experimental data on the dissociation conditions of semi-clathrate hydrates of {carbon dioxide + tetra-n-butyl-ammonium bromide (TBAB)} aqueous solution are first reported in a wide range of TBAB concentrations and at different pressures and temperatures. A thermodynamic model is then proposed to predict the dissociation conditions of the semi-clathrate hydrates for the latter system. The hydrate – TBAB aqueous solution (H-Lw) phase equilibrium prediction is considered based on Gibbs energy minimization approach. A modified van der Waals–Platteeuw solid solution theory developed based on the H-Lw equilibrium information is employed to predict the dissociation conditions of semi-clathrate hydrates of carbon dioxide + TBAB. The properties of the aqueous solution are estimated using the AMSA-NRTL electrolyte model (Considering the association and hydration of ions). The Peng–Robinson equation of state is used for estimating the gas/vapour phase properties. Results show that the proposed model satisfactorily predicts the experimental values with an average absolute relative deviation of approximately 13%.

Research paper thumbnail of Application of artificial neural networks for estimation of solubility of acid gases (H2S and CO2) in 32 commonly ionic liquid and amine solutions

Journal of Natural Gas Science and Engineering, May 1, 2015

Abstract In the present study, the potential use of a model based on an artificial neural network... more Abstract In the present study, the potential use of a model based on an artificial neural network (ANN) was investigated to predict the solubility of acid gases (H2S and CO2) in 32 commonly single and mixed amine and ionic liquid (IL) solutions over wide ranges of operating conditions. Temperature, partial pressure of acid gas (H2S or CO2), overall mass concentration, apparent molecular weight, critical temperature and critical pressure of solution were chosen as input variables of the proposed network. A collection of 733 experimental data points for H2S solubility (including train, test and validation data points) have been gathered from the literature to develop the network. The best parameters of the developed ANN containing the number of neurons, numbers of hidden layer and transfer function were acquired by using these data points. To evaluate the network accuracy, regression analysis with a data set including 169 data points for H2S solubility which were not considered in the training, testing and validation stages was applied. Furthermore, the extrapolation capability of the network was investigated by an extra data set (114 data points for CO2 solubility). The optimized network was trained by the Levenberg–Marquardt back-propagation algorithm with two hidden layers including 8 and 4 neurons and Tan-sigmoid transfer function for the hidden and output layers. The model results show that developed ANN model has ability to estimate accurately the solubility of acid gases in different solutions with Mean Relative Error (MRE) value of 3.104 and correlation coefficient (R2) of 0.997.

Research paper thumbnail of Correlation and Prediction of the Solubility of CO2 and H2S in an Aqueous Solution of 2-Piperidineethanol and Sulfolane

Industrial & Engineering Chemistry Research, 1998

The simplified Clegg-Pitzer equations are used to correlate the solubility data of COâ in the 2-P... more The simplified Clegg-Pitzer equations are used to correlate the solubility data of COâ in the 2-PE (2-piperidineethanol) (45 wt %)-TMS (sulfolane) (40 wt %)-HâO (15 wt %) system at 25, 40, 70, 100, and 130 C and the solubility data of HâS in the 2-PE (45 and 55 wt %)-TMS (40 and 10 wt %)-HâO (15 and 35 wt %) systems at 40 and 100 C. The interaction parameters thus determined can be used to predict the solubility data for the COâ-2-PE (55 wt %)-TMS (10 wt %)-HâO (35 wt %) system at 40 and 100 C and also for the quinary COâ-HâS-2-PE-TMS-HâO system without any additional adjustable parameters. The equations have been proven again to be of use for aqueous solutions containing mixed physical and chemical solvents and ionic species with chemical equilibria.

Research paper thumbnail of Experimental Investigation of Methane Hydrates Equilibrium Condition in the Presence of KNO3, MgSO4, and CuSO4

Journal of Chemical & Engineering Data, 2010

Worldwide demand for natural gas (mainly composed of methane) is ever increasing, therefore; prod... more Worldwide demand for natural gas (mainly composed of methane) is ever increasing, therefore; production and transmission of natural gas from stranded reservoirs becomes increasingly attractive. However, one of the challenges facing the development of these reservoirs is transportation of the produced gas to the market in a safe, efficient and cost-effective manner. Gas hydrates have been considered as a good alternative for storage and transportation media of natural gas produced from the stranded reservoirs, but the most disadvantage of this method is the slow rate of hydrate formation although addition of surfactants and nanoparticles will promote this formation process. In this work, the effects of sodium dodecyl sulfate (SDS) and CuO nanoparticles on the hydrate behavior of methane at 274.65 and 276.65 K temperatures; 5 and 6 MPa initial pressures and in a wide range of concentrations of nanoparticle in aqueous solution have been studied. The results show that by adding these materials, the amounts of gas consumption, the rate of gas consumption and the mole percent of water to hydrate conversion have increased, where this increase is proportional to the nanoparticle concentration used. The results also demonstrate that adding these materials have decreased the induction times, however, have no appreciable effect on the final gas-storage capacity.

Research paper thumbnail of Experimental determination and prediction of methane hydrate stability in alcohols and electrolyte solutions

Fluid Phase Equilibria, 2009

Research paper thumbnail of An Evaluation of Four Electrolyte Models for the Prediction of Thermodynamic Properties of Aqueous Electrolyte Solutions

DOAJ (DOAJ: Directory of Open Access Journals), Apr 1, 2017

In this work, the performance of four electrolyte models for the prediction of the osmotic and ac... more In this work, the performance of four electrolyte models for the prediction of the osmotic and activity coefficients of different aqueous salt solutions at a temperature of 298 K, at atmospheric pressure, and in a wide range of concentrations is evaluated. In two of these models, namely electrolyte non-random two-liquid (e-NRTL) and mean spherical approximation non-random two-liquid (MSA-NRTL), the association between ions of the opposite charges for simplification purposes is ignored, but in the other two ones, namely associative mean spherical approximation non-random two-liquid (AMSA-NRTL) and binding mean spherical approximation (BiMSA), association and solvation effects are considered. The predictions of these four models for the osmotic and activity coefficients of electrolyte solutions at a temperature of 298 K and at atmospheric pressure are compared with the experimental data reported in the literature. This comparison is performed for 28 different aqueous salt solutions, including thio-cyanates, perchlorates, nitrates, hydroxides, quaternary ammonium salts, and others. The results show that the performance of the models which consider association effects is better than the others, especially for higher salt concentrations. However, the best performance belongs to the BiMSA model, which has some parameters with physical meaning.

Research paper thumbnail of Investigating the kinetics of CO2 absorption in aqueous sodium serinate/piperazine solutions: An experimental and mathematical modeling

Journal of environmental chemical engineering, Dec 1, 2022

Research paper thumbnail of Investigating the kinetics of CO2 absorption in aqueous sodium serinate/piperazine solutions: An experimental and mathematical modeling

Journal of Environmental Chemical Engineering

Research paper thumbnail of An Evaluation of Four Electrolyte Models for the Prediction of Thermodynamic Properties of Aqueous Electrolyte Solutions

Iranian Journal of Oil and Gas Science and Technology, 2017

In this work, the performance of four electrolyte models for prediction the osmotic and activity ... more In this work, the performance of four electrolyte models for prediction the osmotic and activity coefficients of different aqueous salt solutions at 298 K, atmospheric pressure and in a wide range of concentrations are evaluated. In two of these models, (electrolyte Non-Random Two-Liquid e-NRTL and Mean Spherical Approximation-Non-Random Two-Liquid MSA-NRTL), association between ions of opposite charges for simplification purposes is ignored and in the other two ones, (Associative Mean Spherical Approximation-Non-Random Two-Liquid AMSA-NRTL and Binding Mean Spherical Approximation BiMSA) association and solvation effects are considered. The predictions of these four models for the osmotic and activity coefficients of electrolyte solutions at 298 K and atmospheric pressure are compared with the experimental data reported in the literature. This comparison includes, 28 different aqueous salt solutions including thio-cyanates, perchlorates, nitrates, hydroxides, quaternary ammonium sal...

Research paper thumbnail of Natural gas hydrate stability conditions and water activity in aqueous solutions containing mono ethylene glycol (MEG) and salt: Experimental measurements and thermodynamic modeling

Fluid Phase Equilibria, 2021

Research paper thumbnail of Decrease in evaporative loss of volatile fuels using new mixture of surfactants

Petroleum Science and Technology, 2021

Abstract Despite the economic aspects of evaporative losses of volatile hydrocarbons such as gaso... more Abstract Despite the economic aspects of evaporative losses of volatile hydrocarbons such as gasoline, problems in the form of fire hazards and environmental pollutions are also concerned. Today many options to reduce the evaporation of hydrocarbon liquids are offered and used worldwide but none of them can impressively prevent the process. In this work, the potential use of mixture of surfactants as liquid film coating layer on free surface of volatile fuels was investigated to decrease the evaporative loss of gasoline and oil in fuel tanks. A combination of surfactants and polyethylene glycol were considered as liquid film that can be applied to spread on the surface of gasoline and oil. The prepared liquid film can remain on the surface of gasoline for about 5 hr and on the surface of oil for more than 55 hr. Obtained results indicate that by using the covering film, the evaporation losses of gasoline and oil at 25° C and atmospheric pressure in a time interval of 200 min are reduced by 20.92 and 70.83%, respectively. So, using a mixture of surfactant and polymer (as a covering film) can reduce the evaporation loss of hydrocarbons appreciably. The use of non-carcinogenic surfactants, increasing the durability of the coating layer on the gasoline surface and significantly reducing the evaporative loss of gasoline are some of the innovations of this research.

Research paper thumbnail of Experimental measurement and prediction of carbon dioxide clathrate hydrate phase boundary in presence of ethanol + sodium chloride, potassium chloride, magnesium chloride and calcium chloride aqueous solution

Petroleum Science and Technology, 2019

The dissociation condition of clathrate hydrate of carbon dioxide in aqueous solutions of ethanol... more The dissociation condition of clathrate hydrate of carbon dioxide in aqueous solutions of ethanol þ NaCl, KCl, MgCl 2 and CaCl 2 are measured in the temperature range of (259.4-274.7) K and pressures up to 3.7 MPa. Isochoric pressure-search method is used for all measurements. In addition for the first time in open literature a machine learning algorithm model based on artificial neural network is developed to predict equilibrium temperatures. Absolute relative deviation (ARD) and correlation coefficient (R 2) for trained neural network are 0.0305 and 0.9994, respectively.

Research paper thumbnail of Prediction of acid gas solubility in amine, ionic liquid and amino acid salt solutions using artificial neural network and evaluating with new experimental measurements

Journal of Natural Gas Science and Engineering, 2016

Abstract In this work presented here attempt is prediction of acid gases (carbon dioxide and hydr... more Abstract In this work presented here attempt is prediction of acid gases (carbon dioxide and hydrogen sulfide) loading capacities by employing artificial neural network (ANN) model in 51 single and blended alkanolamine, ionic liquid and amino acid salt solutions as commonly and new industrial absorbents in large domain of operational conditions. Also for evaluating extrapolation capability of ANN, new experimental data on CO2 solubility in aqueous solutions of Potassium Glycinate blended with Piperazine (PZ) and 2-amino-2-methyl-1-propanol (AMP) at different temperatures and pressures are measured. It should be mention that CO2 solubility data for these two solutions are not available in literature. For developing ANN, solution pH, total mass concentration, partial pressure of CO2 and H2S, apparent molecular weight, critical temperature, critical pressure and temperature are assumed as inputs. A band of 2982 experimental data points for CO2 and H2S loading capacities have been collected from literature to create the suggested ANN. The best structure of the suggested network is achieved by employing these literature data points. The network is trained by algorithm of Levenberg–Marquardt back-propagation, consists of 9 and 6 neurons in first and second hidden layers, respectively. For the hidden and output layers, Tan-sigmoid transfer function is utilized. The output results of developed network show that suggested network that is created with solubility data of single and blended alkanolamine, ionic liquid and amino acid salt solutions has capability to predict accurately CO2 and H2S loading capacities in dissimilar commonly and new industrial solutions with Average Relative Deviation (ARD %) equal to 2.7992, Mean Square Error (MSE) value of 3.7468 × 10−5 and correlation coefficient (R2) equal to 0.9984.

Research paper thumbnail of CO 2 solubility in aqueous solutions of potassium prolinate and (potassium prolinate + 2-amino-2-methyl-1-propanol) as new absorbents

Journal of Natural Gas Science and Engineering, 2016

Please cite this article as: Hamzehie, M.E., Najibi, H., CO 2 solubility in aqueous solutions of ... more Please cite this article as: Hamzehie, M.E., Najibi, H., CO 2 solubility in aqueous solutions of potassium prolinate and (potassium prolinate + 2-amino-2-methyl-1-propanol) as new absorbents,

Research paper thumbnail of Prediction of carbon dioxide loading capacity in amino acid salt solutions as new absorbents using artificial neural network and Deshmukh–Mather models

Journal of Natural Gas Science and Engineering, 2015

The aim of this work issolubility prediction of carbon dioxide (CO 2) in amino acid salt solution... more The aim of this work issolubility prediction of carbon dioxide (CO 2) in amino acid salt solutions as new absorbents over wide ranges of operating conditions, utilizing Artificial Neural Network (ANN) and Deshmukh-Mather models. pH of solutions, overall molar concentration, partial pressure of CO 2 , apparent molecular weight and temperature was picked as input variables of the proposed ANN. A group of 1364 literature experimental data points for CO 2 solubility have been congregated from the literature to build the network. The best architecture of the developed ANN including the numbers of hidden layer, transfer function and number of neurons were attained by utilizing these literature data points. Also CO 2 solubility in amino acid salt solution was modeled using Deshmukh-Mather model. Results show that proposed ANN has better performance compared to Deshmukh-Mather model.The ANN was trained by the Levenberg-Marquardt backpropagation algorithm including two hidden layers with 8 and 7 neurons and Tan-sigmoid transfer function for the hidden and output layers. The model results show that proposed ANN that developed with amino acid salt solutions data points has ability to predict accurately the

Research paper thumbnail of Experimental and theoretical study of carbon dioxide solubility in aqueous solution of potassium glycinate blended with piperazine as new absorbents

Journal of CO2 Utilization, 2016

Abstract In this work aqueous solution of potassium glycinate, piperazine and potassium glycinate... more Abstract In this work aqueous solution of potassium glycinate, piperazine and potassium glycinate blended with piperazine have been utilized through CO 2 solubility measurements in order to investigate the possible use of these salts of amino acid blended with alkanolamine for CO 2 absorption. The equilibrium solubility of CO 2 for aqueous solutions of potassium glycinate, piperazine and potassium glycinate blended with piperazine at 1.0, 4.0 and 10.0 wt.% overall mass concentration are experimentally measured with an equilibrium cell at CO 2 partial pressure ranging from 5.1 to 2508.7 kPa and temperatures between 293.15 and 323.15 K. Obtained data show that loading capacity decreases with increase in temperature and concentration of potassium glycinate and potassium glycinate blended with piperazine. Obtained CO 2 loadings are very high at low concentration of potassium glycinate. In order to predict CO 2 solubility in aqueous solutions potassium glycinate, piperazine and potassium glycinate blended with piperazine, Deshmkh-Mather model is extended. The values of MSE, ARD and R 2 for the extended Deshmukh-Mather model are 0.0741, 8.9582 and 0.9826, respectively. In addition, an artificial neural network (ANN) is developed to predict CO 2 solubility in aqueous solutions of piperazine, potassium glycinate and potassium glycinate blended with piperazine. The values of MSE, ARD and R 2 for the optimal trained ANN are 0.0179, 4.1528 and 0.9962, respectively.

Research paper thumbnail of Theoretical and experimental study of phase equilibrium of semi-clathrate hydrates of methane + tetra-n-butyl-ammonium bromide aqueous solution

Journal of Natural Gas Science and Engineering, 2015

Abstract In this study, the phase stability conditions of semi-clathrate hydrate of methane + tet... more Abstract In this study, the phase stability conditions of semi-clathrate hydrate of methane + tetra-n-butyl-ammonium bromide (TBAB) + water system is investigated. New experimental data on the hydrate–liquid–vapor equilibrium conditions of this system is measured. The measured data is for the pressure range of 2.88–14.1 MPa, temperature range of 285.6–295.9 K and TBAB mass fractions of 0.05, 0.15 and 0.3. A thermodynamic model is also developed to predict the phase stability conditions of hydrate for this system. In the developed model, the phase equilibrium of the hydrate of pure TBAB in water is predicted based on the Gibbs free energy minimization technique. This model is then combined with the statistical thermodynamic model of van der Waals–Platteeuw (vdW–P) to predict the phase stability conditions of semi-clathrate hydrate of methane with TBAB in aqueous solution. Binding mean spherical approximation (BiMSA) electrolyte model is used for aqueous phase properties prediction and modified Peng–Robinson equation of state (PR-EoS) is used for calculation of the gaseous phase properties. The results show that the developed model satisfactorily predicts the experimental data with Average Absolute Relative Deviation (AARD) of 12%. Moreover, the model is able to predict the different types of pure TBAB semi-clathrate hydrates and also the inhibition and promotion effects of this salt. The results also show that considering the association effect in the electrolyte model, can improve the predictions of the developed thermodynamic model for hydrate phase equilibrium of methane in the presence of TBAB aqueous solution.

Research paper thumbnail of Carbon dioxide loading capacity in aqueous solution of Potassium salt of Proline blended with Piperazine as new absorbents

Thermochimica Acta, 2016

Research Highlights  CO2 solubility in solutions of potassium prolinate + piperazine is measured... more Research Highlights  CO2 solubility in solutions of potassium prolinate + piperazine is measured.  Solution of potassium prolinate + piperazine has very high loading capacity.